1. Field of the Invention
This invention relates generally to the area of heating and cooling systems, and more specifically to electronic control systems designed to increase the efficiency of central heating and cooling air conditioning systems.
2. Description of the Prior Art
Heretofore, temperature control systems for use with heating and air conditioning units, hereinafter referred to as "HVACs," have consisted of thermostats which turn the heating or cooling unit on or off when a given temperature is reached. Further improvements have been accomplished through the use of timers which limit the period of use of the HVAC. Additional improvements have included controls using a relay together with a time delay in conjunction with a thermostat, so that the fan operates for a preset time after the HVAC unit is turned off, thereby clearing the duct of any available warm or cool air. Applicant is unaware of any prior art teaching a device or method which combines a differential thermostat sensing both the supply and return duct temperatures with a computerized control unit having the unique features as taught herein.